It is estimated that two to three million people are saved every year due to vaccinations, therefore it is hailed as one of the best achievements in public health. Vaccines have been used to successfully eradicate smallpox in 1979 as part of the first successful mass vaccination programme. Vaccines have been used to almost eradicate polio and measles which used to be deadly. There are over 30 different infectious diseases, and many can be prevented with a single vaccine.
Importance of vaccine: small generic statement
Vaccines induce a protective immune response to the targeted pathogen without the risk of contracting the disease leading to morbidity and mortality in some cases.
The aim of vaccination produces memory cells that can produce antibodies to fight of the pathogen if it invades the body without getting the disease and suffering from its potential harmful complications.
In addition to protecting the individual against the pathogen, vaccines also protect people who are unvaccinated such as people who are not able to be vaccinated due to weak immune system. This is because the more people are immune to a specific pathogen the lower the chance of transmission from one person to another, this limits the number of vulnerable people exposed to the pathogen. This indirect protection, called herd protection, however it requires that a large portion of the population (75–95% depending on the disease), or a special group that plays a key role in transmission of the disease, is vaccinated. Herd protection is often essential for the success of vaccination programs, such as for measles.
Vaccination of pregnant women can also indirectly protect infants in their first months of life through transfer of maternal antibodies from the mother to the foetus across the placenta. This concept has been successfully established for tetanus, influenza and pertussis. This is essential as fetus do not have as memory cells as an adult. (I don’t know why I wrote this cut it out if it isn’t good)
Vaccinates can protect certain high-risk populations from the infection so they do not suffer the complications. However, the vaccines are not effective with every segment of the populations. Therefore, the herd effect is important as it means that people who are not directly targeted by the vaccination programme also benefit, because there is a prevalence of immunity it prevents the circulation of infectious diseases as there are less people to pass it on to and spread it. Infectious diseases such as small pox was eradicated using the idea of herd immunity as there was high uptakes of the vaccination most of the population became immune to it so the smallpox could not be passed on and became eradicated. Herd immunity gas also decreased the transmission of pertussis and against influenza and pneumococcal disease. Therefore, it is essential that there is a high uptake of vaccines so that the chance of disease spreading is reduced.
Cost benefit of vaccine influenza https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4521706/
Seasonal influenza is the cause of a substantial cases of morbidity and mortality in people of all ages, and influenza vaccination is recommended to be given to everyone over the age of 6 months since the year 2010. A study was done into the averted outcomes due to influenza vaccination for influenza seasons 2005-06, 2006-07, 2007-08, and 2008-09, and age cohorts 6 months-4 years, 5-19 years, 20-64 years, and 65 years and above. Costs were calculated according to a payer and societal perspective (in 2009 US$) and considered medical costs and productivity losses.
When taking the cost per patient into consideration, influenza vaccination was cost saving for individuals over the age of 65 in seasons 2005-06 and 2007-08. In the same study it is stated that, influenza vaccination cost $US 1.7 billion in total in the year in 2006-07 and $US 1.8 billion in 2008-09. However, when looking at the socioeconomic perspective when including the lost earnings due to premature death the vaccination lead to cost savings for all ages overall combined in season 07-08. However, this does not consider that the older age group may affect the results
Influenza vaccination was cost saving in the older age group (65≥) when considering productivity losses and, in some seasons, when taking into account medical costs only. Averted costs vary significantly per season; however, in seasons where the averted burden of deaths is high in the older age group, averted productivity losses due to premature death tilt overall seasonal results towards savings.
In this study the indirect vaccination effects such as herd immunity and the potential fewer cases and therefore more cost savings resulting from this was not furthermore this study does not take the extra burden on patients if they are vaccinated and then contract, this could mean the benefits of the influenza vaccine may be greater than what is mentioned in this study.
Influenza vaccination has been recommended for all persons aged six months of age and older since 2010 . In the U.S. each year, seasonal influenza has been estimated to cause 31.4 million outpatient visits, >200000 hospitalizations, 3000–49000 deaths, and is responsible for 44.0 million days lost ( estimations based on 2003 population) [1,3]. While most morbidity occurs in persons ≥65 years of age, all age groups are affected.
Measles was the single most lethal infectious agent widespread use of live attenuated measles vaccine discovered in 1963. In the early 1960s, as many as 135 million cases of measles and over 6 million measles-related deaths are estimated to have occurred yearly globally. Additionally, measles supressed the patients' immune system leaving them vulnerable to other diseases such as pneumonia, diarrhoea, and acute encephalitis. Pneumonia, either a primary viral pneumonia or a bacterial superinfection, is a contributing factor in about 60% of measles-related deaths. The introduction of routine measles vaccination in most developing countries during the 1980s as part of the Expanded Programme on Immunization had a major effect on global measles mortality. By 1987, WHO estimated that the number of deaths from measles worldwide had been reduced to 1·9 million. This shows the importance of a good vaccination programme
Many country lacks sufficient vaccination coverage. In WEIRD (Western, Educated, Industrialized, Rich, and Democratic) societies, opposition to vaccination has a long story (Poland and Jacobson 2011). Certain people question being vaccination, because they perceive it to be unsafe because of the abundance of widely available poor science and claims of harm related to vaccines. This leads to hesitancy leads an increase in vaccination delay and refusal, which leads to an outbreak of of vaccine-preventable infectious disease which can sometimes lead to fatalities. A fall in the level of vaccinations lead to a measles outbreak in Europe in 2018 lead to 41,000 cases of morbidity and 37 mortalities (WHO 2018). Measles is still an endemic disease in WEIRD countries (Altpeter et al. 2018). Refusal or delaying the vaccination not only puts the individual under risk but it also puts the whole community at risk as there are some segments of the population who cannot be vaccinated. The ethical dilemma is whether to respect the patients autonomy or acting in the best interest of the public’s safety.
In developing nations in Africa for example, the vaccination coverage has historically been low despite parents wanting to vaccinate their children against infectious diseases which are vaccine preventable. Routine childhood vaccination programs lead to a decline in the cases of morbidity and mortality, however this leads many people to then question the point of vaccinating as the actual disease is not very common people do not realise the dangers of not vaccinating. Immunization has significantly improved public health in the African Region, including the elimination of many life-threatening infectious diseases. This has lead to a decrease in the number of hospitalisations in relation to vaccine preventable diseases since the introduction of new effective vaccines. However, optimizing the benefits of immunization by achieving high universal coverage has met with many challenges. The Regional immunization coverage, though raised from its low 57% in 2000 to 76% in 2015 has remained below expected target(1). However the rate of immunization has stagnated around 70% for a prolonged period(1). Cases of unequal access to immunization service continue to be a problem in the area.
Vaccination of vulnerable populations
Migrants and refugees are extremely vulnerable, due to their lower vaccination coverage than the host community, because they face many more barriers to vaccination (e.g., socioeconomic inequalities. They have a reduced immunization rate, similar to their country of origin where they lack access to immunization service. As a result of this the refugees or migrants are not inoculated against parasites in the UK.
Some groups of vulnerable people suffer from a disproportionate amount of cases of vaccine-preventable diseases. The low vaccination coverage among migrants can decrease herd immunity and this will lead to more of the public getting infected as there are more people the pathogen can transmit by. This will then lead to people with weaker immune system getting infected and therefore dying. As there is a high immunization uptake and because migrants are often proactive about their health (Hargreaves et al. 2018), there are promising opportunities of successful catch-up vaccination.
Reaching migrants is challenging, so all opportunities for catch-up vaccination should be used. This includes free vaccination in areas with a large number of people who are not vaccinated, such as in a migrant centre. These vaccination programmes should be extended to adults as they are also likely to contract and disseminate vaccine-preventable diseases.
Morbidity and mortality vary per season, depending on the types, subtypes and phenotypes of the circulating influenza viruses, levels of prior natural immunity, as well as on the antigenic match between the seasonal vaccine with the circulating viruses.
People used to be vaccinated separately for each disease. However now thanks to further research it is possible to create combinations vaccines, reducing the number of injections required for immunization against certain diseases. The most commonly used combination against measles today is MMR, which covers measles, mumps and rubella.
Multiple studies have disproved the link between the MMR vaccine and autism. The most recent example is a large Danish study: The study accompanied more than half a million Danish children over ten years and couldn’t find any increased risk for autism caused by the MMR vaccine. Out of 657, 461 children 6,517 children were diagnosed with autism. Comparing MMR-vaccinated with MMR-unvaccinated children gave a result of 0.93 for the autism hazard ratio, therefore there is no significant risk. Furthermore, there was no increased risk for autism after MMR vaccination in children with sibling history of autism and autism risk factors or other vaccinations during their childhood. However, despite this the hypothesized link between the MMR vaccination and autism, due to the retracted Lancet paper from 1998 written by Andrew Wakefield the amount of vaccine hesitancy increased.
All the cases morbidity and mortality prevented by the direct and indirect effects of vaccination will save money in healthcare, which can then be used to treat other medical conditions. Therefore, it is imperative that we stop the spread of misinformation and instead circulate of scientifically proven facts and help people understand the basic concepts of vaccines so the public understand their high benefits to risk ratio and the outcome if they or their child gets infected as a result of not being vaccinated so that a higher proportion of people who can be vaccinated are being vaccinated. So that herd immunity is achieved and segments of the population who cannot be vaccinated are also protected. Education and information strategies should emphasize on vaccines’ safety and effectiveness.
New vaccines types of vaccines are required to immunize people against pathogens with multiple serotypes such as dengue. Another issue is antigenic hypervariability such as with HIV (human immunodeficiency virus) and current vaccines do not work for this as the vaccine will only immunise people against the pathogen with a specific antigen and any memory cells produced from that vaccination. The more effective the vaccine the more people will agree to be vaccinated as they see all the positives it is doing.